On 10/18/2011 1:19 PM, Jeff Scott wrote: > The biggest issue with the one I pointed to on ebay (which is the one I am > using) is the 1 amp limitation. It doesn't take a lot of incandecent bulbs to > add up to 1 amp, although most modern panels are far less than that. When > this unit hits a 1 amp or higher draw, it crowbars and shuts off. You have to > shut it off for 30 seconds for it to reset. However, you can also buy 8 amp > units as well. I can't imagine anyone would be pulling that kind of current > with their panel lights. The advantage to it is that it is a switching power > supply, so does not have to dissipate heat like a resistive rheostat. > > Jeff Scott > Los Alamos, NM This current limit can be overcome by using the PWM to drive a 2N3055 Transistor, the output of which connects to the Lamps/LED's. The 3055 is capable of delivering up to 15A. If you send me schematic of this PWM, I can show you how to add it into the circuit. There are other transistors which are available at Radio Shack which would also be appropriate, Such as the TIP31.
If you like to build things on your own, the following link shows how the 555 timer is used for this purpose: http://pcbheaven.com/circuitpages/LED_PWM_Dimmer/ I personally would use LED's over incandescent bulbs any day, twice on Sundays. -- Glenn Martin KR2 N1333A, Biloxi, MS
